Storage battery



Patented Jan. 8, 1924.

UNITED STATES PATENT OFFICE.

HORACE M. WILLIAMS, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO ELECTROL-MANUFAGTURING COMPANY, A CORPORATION OF RHODE ISLAND.

STORAGE BATTERY.

No Drawing. Application filed October 15, 1919, Serial No. 330,893.Renewed May 5, 1923.

To all whom it'may concern:

Be it known that I, HORACE M. WILLIAMS, a citizen of the United Statesof America,

residing at Providence, county of Provi-. dence, State of Rhode Islandhave inventedv certain new and useful Improvements in Storage Batteries,of which the following is a specification.

My invention relates to electric batteries and comprises a solidelectrolyte for sec ondary or storage batteries, the battery formedtherewith and process of making same. This electrolyte is as efficienta's'the best liquid electrolyte now known and more advantageousin'manyways and much more convenient to handle. My invention 'applies tothe standard formof secondary or 5 storage battery as now commonlyemployed using lead plates and sulphuric acid, and in substance involvesthe mixture with such sulphuric 'acid of a material which cobut whichserves as a solid vehicle for retaining a residual volume ofacid inoperative relation with the lead plates.

What- I ever-the 'trueanalysis of the operation the result is the fullbattery output of current, and also the exercising by this solidelectrolyte of the function of the usual separators, in holding thebattery plates properly separated each from the other and in normaloperative position.

According to my present information the material to be added as aboveshould be commerical silicate of soda, sometimes called water glass,mixed with methyl salicylate which is commonly known as synthetic oil ofWintergreen. Still further improved results are secured if a smallproportion of a coal tar product such as the material known commerciallyas VVests disinfectant is added to the silicate of soda. According to mybest present information the preferred method of carrying out myinvention is the .following:

i I first mix about one -.gallon of liquid silicate of soda with aboutone fluid ounce of each of the two materials mentioned above. This Idilute with about three gallons of water and add five gallons of asulphuric acid solution of 1400 specific gravity. The more concentratedsulphuric acid of commerical form having a density of 1850 specificgravity may be used, if

more of the original solution is employed, but it produces much heat onmixing with the silicate of soda solution. This heating action isinconvenien't and might destroy the vessel containing the mixture and Iprefer to use the more dilute form of the acid as specificed. Themixture soonbegins to set or change into a flocculent precipitate, andin from one to two hours the transformation from liquid tosolid iscomplete so far as the eye can see, and the result is a damp jelly-likemass.

The mixture of the silicate of soda solution and the acid is made in anysuitable vessel in which a homogeneous mixture can be easily producedand is then poured into the battery cells, the usual separator-spreferably having first been removed from between the plates, as mysolid electrolyte exerts a more perfect spacing and separating actionthan any wooden or other separator plates. Just so much dead space andmaterial can thus be eliminated from the b.- tery cell and activeelectrolytic material substituted therefor. Such separators may be leftin position if desired. The mixture may, if desired, be made in thebattery jar itself.

When the mixture of the above proportions solidifies it is transformedinto a damp paste-like mass which is mainly colloidal silica, formed bythe reaction between the silicate of soda and a portion of the sulphuricacid. This is a highly porous mineral body and in its pores the residualacid, the coal tar product and the methyl salicylate are, held insuspension. If the proportion of silicate of soda is increased inquantity the resultant product is harder and tougher and if the increaseof the" silicate afl'ord freedom of circulation for the suspended fluidsand gases evolved by the ellectroliytic action when the battery is discar .of soda component is carried far enough T the product ultimatelybecomes too hard to The function of the methyl salicylate has beenaccomplished, more intimate contact is established and maintainedbetween the plates and the electrolyte.

T e advantages of my invention are obvious. The creeping and fumingdestructive action of the liquid sulphuric acid electrolyte is entirelyehminated. As the small amount of liquid present is held in suspensionin a mineral sponge-like body, the battery can be tipped over to anyangle without affecting its action. As there is noypossibility of theplates buckling the battery will stand overcharging without seriousresults. In fact old batteries with cracked plates work like newoneswhen my invention is applied to them. No sulphating of the platesoccurs whenthe battery stands' idle. The sulphated plates of oldbatteries are cleaned by the mixture and there are no separating platesor similar devices to deteriorate with age.

As the material shakes down with use or otherwise slowly decreases involume from essential, delicate and easily destructible feature of thestandard lead battery and other cause, and thus maintaining the platesare frequently broken up by the ebb and flow of a liquid electrolyte andother disturbing influences, and accumulate in the bottom of the cellas'so much sediment. In contradistinction to thisdestructive action ofthe usual liquid electrolyte on the fine branchiform masses of activematerial which exist when the battery is at its high est efliciency, mysolid electrolyte forms a matri'rand support for these delicatestructures, preventing their falling from the lead plates from theaction of gravity, or any in their most eflicient condition.

An important feature of my invention 15 the non-fusibility of the body.of colloidal serving as a matrixfor the electrolyte, and

silica, holding the electrolyte. :Even when subjected to high heat thismaterial merely dries out without melting or fusing, Consequently noamount of'heat apphed either externally or internally to a batteryequipped with my electrolyte, below that which would fusethe leadplates, has any serious deleterious efiect'other than to d out the waterwhich can be readily replace Batteries constructed according to myinvention can be subjected to freezing temperature without injury asthere is little or no freezing expansion of the small amount of water inthe residual acid held in-a finely divided state in the colloidal silicasponge like body, and the plates are not broken thereby. Comparativetests made with standard cells equipped with my inventionhave shown aninternal resistance of only ten hundredths of an ,ohm, as 1 that afterthe alkaline portionof the mixture has. combined with its correspondingamount of acid, the residual acidsolution left in the pores of thecoloidal silica mass will have a specific gravity about e ual to that ofthe standard sulphuric aci electrolyte. The above stated proportionswill secure this result approximately and have given excellent resultsin extensive practical use, but I am pursuing further .investigations inthe effort to determine more exactly the proportions necessary toproduce the residual electrolytes best adapted for different kinds ofbatteries, and for batterie's'of the same kind required for difierentkinds of duty.

Having described my invention I claim:

1. An electric storagebattery having, in combination with the usual leadplates, at body of colloidal silica precipitated in situ ving as amatrix and an electrolyte in s spension in said body comprising asulphuric acid solution "mixed with a minor quantity of methyl saliclate.

2. An electric storagebatteryhaving, in

combination with the usual lead plates, a

body of colloidal silica, precipitated in situ serving as amatrix forthe electrolyte, and an electrolyte in suspension in said bodycomprising a sulphuric acid solption mixed witha minor quantity of aliquid coal tar product. 7 a

3. Ancelectric storage battery having, in combination with the usuallead plates, 0. body of colloidal silica precipitatediin situ anelectrolyte in suspension in said body comprising a sulphuric acidsolution mixed with a minor quantity oi methyl salicylate and a liquidcoal tar product.

4. An electrolyte for storage batteries having lead plates whichcomprises 'a sul- HORACE M. WILLIAMS

